This invention relates to an automatic flushing system for flushing at once a plurality of toilet bowls installed in a lavatory.
Public lavatories in the buildings, railway stations or the like are provided each with a relatively large number of stools and urinals. In such a public lavatory the users should operate the flushing system to flush the stools or urinals they have just used. But the users often forget to operate the flushing system, thus leaving the lavatory in an unhygienic condition. To keep clean the toilet bowls of a public lavatory, use has been made commonly of an automatic flushing system which flushes all the toilet bowls automatically at predetermined intervals. This system, however, is extremely uneconomical. It wastes a great amount of water since the toilet bowls are flushed repeatedly even if none of them is used for a long time, for example in the midnight-to-morning period. To save water, the attendant must turn off the timer of the flushing system late at night and turn it on early in the morning next day, thereby to keep the toilet bowls unflushed during the midnight-to-morning period. This is a drawback of this flushing system.
To eliminate the drawback of the above-mentioned flushing system, there has been invented an automatic flushing system which flushes toilet bowls every time a predetermined number of persons are detected to have used the lavatory. As well known, public lavatories are used at an irregular frequency. If a lavatory with such an automatic flushing system is used at a low frequency, its toilet bowls are left unflushed for a long time. Thus, the lavatory may often get dirty and give forth an offending smell outside. For this reason this automatic flushing system cannot be employed in public lavatories at any places.